Mr Hampton was asked by reporters afterwards whether China was responsible for any of the attacks cited by him at the committee hearing.

"In terms of cyber security New Zealand is subject to attacks from a range of state actors, we go through a very careful and deliberate process when we attributed - we won't be doing any random attributions today."

The GCSB recorded 347 cyber security incidents in the last financial year.

It said 134 of those "contained indicators that have been linked to known state-sponsored cyber actors", up nearly 10 percent on the year before.

GCSB says it was under no pressure from politicians to make the decision to turn down Huawei's bid for partnership in Spark's 5G rollout. Photo: AFP / Imaginechina

Mr Hampton told MPs his was a regulatory function, but he made direct reference to diplomatic and political pressure.

"I would like to assure the Committee that in making my decision at no point was I under direct or indirect pressure from any party," Mr Hampton said.

"My decision was independent from ministers and while we share intelligence with Five Eyes partners, there was no pressure, requests or demands made by partners, either publicly or privately, to ban any vendor."

For the first time, the GSCB also alluded to its role assisting Customs, under the Intelligence and Security Act.

"Through our signals intelligence capabilities we are supporting NZ Customs to better target transnational crime networks with the aim of disrupting their efforts 'upstream' - before their activities can impact on New Zealand," Mr Hampton said.

Foreign interference in democratic processes

Security Intelligence Service Director-General Rebecca Kitteridge talked about New Zealand as, like other countries, being the target of "foreign interference and espionage", which she said was a high priority for the agency.

Foreign intelligence agencies had the "intent and capability" and she listed the motives: trying to get hold of New Zealand information, intellectual property and technology, covertly gaining influence over decision-makers and pressuring individuals and communities to "subscribe to particular views or actions".

Within the context of concerns around foreign interference in the 2016 US Presidential election and the Brexit vote, Ms Kitteridge said work had been done ahead of the 2017 election in New Zealand.

SIS Director-General Rebecca Kitteridge says New Zealand was just like other countries in being a target for foreign interference. Photo: RNZ / Alexander Robertson

"To work out the kind of steps if we saw that kind of activity in New Zealand and I'm thankful to say we didn't but I don't think we should be complacent."

She said New Zealand had to be very alert to the fact that because of its "precious, open, liberal democracy", this country does have "vulnerabilities" to foreign interference.

Ms Kitteridge said the SIS was aware of a "small but concerning" number of New Zealand citizens, some of whom have dual citizenship, who are likely to still be in the conflict zone in Syria.

She said the agency was not aware of any of those people having returned to New Zealand, but wouldn't comment on whether it was aware of any still intending to come home.

New Zealanders warned about internet use

"Don't be a Dave" - that's the GCSBs message to New Zealanders using the internet in government, business and at home.

Mr Hampton made the point that even the most sophisticated cyber security networks cannot protect against human error, quoting former Australian Prime Minister Malcolm Turnbull.

He went to tell MPs even in the most highly-classified environments, there are still risks.

"Our finance team got an email from me asking to transfer a whole lot of money..."

Ms Kitteridge interjected to clarify the situation: "they didn't click on it though, did they?"

Mr Hampton carried on saying you don't want to be a "Dave" - someone who clicks on everything that comes up on their screen.